Ferret leak

[chris vickery]

A friend wanted me to ask for some expert opinions regarding his ferret. The engine is a B60 Rolls Royce which runs fantastic with great compression etc. All gone over, very clean, new everything including a head gasket which was replaced during an inspection of the engine.
Problem encountered is a small leak of coolant into the engine oil. Suggestion is that the gasket needs to be re-torqued or the gasket maybe faulty. Another idea was that proper installation necessitates the use of sealant as well.
Opinions appreciated, does this represent a major problem? I know that I've changed a couple auto engine head gaskets and fixed this situation rather easily without further complications.
What's up?:

[Geoff Winnington-Ball (RIP)]

Chris,

My experience with something like this has been with a cracked block. Nothing will leak until it's under pressure and hot. I've never had any problems with head gaskets, and if was the top end, you'd know about it from other symptoms.

One question, though... when the head was off, was it machined before reinstallation? If it was overheated at any time, and reinstalled with nothing more than a new gasket, that might do it (although I suspect you might see residuals leaking out of it).

Keep us posted.

[chris vickery]

No apparent leakage on exterior of engine. Head was not machined. Maybe? Will check into.

[Richard Farrant]

Chris,
I have had a lot of experience both with Ferrets and Rolls B series engines and would have good guess that the head is bowed and requires refacing. Also, the head gasket requires rechecking after running. As its a copper /asbestos gasket, I prefer to use Wellseal sealant (originally,a RR formulated product), a kind of shellac.

There are a small number of nuts that you may not be able to use a torque wrench / socket on, these are along the edge of the head, spark plug side, it may be that these are not tightened as much as the others.

Richard

[chris vickery]

Richard, thank you for the advice. Is the B60 engine a fairly reliable beast? What are the possibilities of a cracked block?
Finally is a B60 Humber truck motor the same as used in the feret? I know there are the ancilliaries to swap, anything else to worry about?

[Richard Farrant]

Originally posted by chris vickery
Is the B60 engine a fairly reliable beast? What are the possibilities of a cracked block?
Finally is a B60 Humber truck motor the same as used in the feret? I know there are the ancilliaries to swap, anything else to worry about?

Chris,
They are pretty reliable motors, providing the side exhaust valve clearances are not neglected. Cracked block......its difficult to say from here, but I would remove the head and lay a straight edge over its face, that should show you where the problem is.

A Humber B60 motor will have to have the sump and oil pumps exchanged, as the Ferret is dry sump with a scavenge pump to return oil to tank. The other major thing is to swap the flywhels, Ferret has fluid coupling and Humber a clutch. The rest is only minor fittings.

Richard

Originally posted by chris vickery
Richard, thank you for the advice. Is the B60 engine a fairly reliable beast? What are the possibilities of a cracked block?
Finally is a B60 Humber truck motor the same as used in the feret? I know there are the ancilliaries to swap, anything else to worry about?

Chris,
The whole B Range engines are very robust but they do fail very occasionally, if you didn't know the number tells you a lot:
B = RR Gasoline engine (but often not made by RR!)
number = cylinders
0 or 1 = 3.5" or 3.75" bore.
The intention was to have a range of engines with common parts although the B41 and B61 were never made as the MoD requirements were met with the B40, B60, B80 and B81.

You can certainly re-configure any basic engine into another type and mark number, the B81 is the only slightly difficult one as the Mk.7 and onwards have different cams and CR.

The design is very old being based on a 30's Bentley engine with the design started early in WWII, some 8cyl versions were trialled during WWII.

There are a few traps for the unwary which become obvious when reading the RR Wksp Manual TSD 702.

The head gasket requires the sealing cement defined, which flies in the face of accepted practice, and along the exhaust side only to a width of 1" on both faces.

The unwary often over-tighten the heads, 35-40lbs ft is the spec, the nuts along the exhaust side are eclipsed by the casting overhang. RR say to use a box spanner with a tommy bar centrally and 6" long; the inference being as much as you can pull on such a lever!!

Main and big-end nuts have no torque setting but are tightened to a specific bolt stretch; 4 - 7 thou on bigend caps, surprisingly TSD 702 gives no figure for main bearing caps. EMER Power S 524 part 2 however gives 440 - 470 lb in for all 3/8" main cap nuts and 340 - 370 lb in for 5/16" main cap bolts. It also gives 6 - 9 thou stretch for bigend bolts.

There are no camshaft timing marks, it is timed by the classical methods using the gear teeth and the eight timing gearwheel bolts like a vernier coupling - best left alone !

All B Range engines are and must be ignition timed statically, 0deg to 2deg AFTER TDC, yes AFTER. The distributor intentionally begins the advance around idle revs and the timing allows hand cranking without danger.

Except the B40, the distributors are subtle twin point affairs that both fire alternate cylinders on alternate points and also take turns in effecting dwell angle extension for better high speed sparks. You will note the 6 cyl distributors have only 3 cam lobes and the eights only 4!! The phasing between point sets is critical or else half the engine can be mis-timed as the distributor is set to the engine against one set only assuming the other set is correctly phased.

This is easy on a six as the points are 90 deg apart making 180deg firings, you can time No1 and No6 cyls from the flywheel marks. on an eight it is essential to remove the distributor and use a bench jig.

They can of course have cracked blocks or failed liners, especially if a previous owner has not religiously used antifreeze which they should have at all times. The core plugs (or as the Americans have it, freeze-out plugs - which they never do anyway) are all screwed (unified special thread too) and cannot push out under freezing conditions.

R.

[Richard Farrant]

Originally posted by FV623
B61 were never made

As a point of fact, B61 were produced in quite large numbers, as I have worked on them.

The unwary often over-tighten the heads, 35-40lbs ft is the spec, the nuts along the exhaust side are eclipsed by the casting overhang.

I have made a special tool to fit the torque wrench to enable these to be tightened correctly.


The core plugs (or as the Americans have it, freeze-out plugs - which they never do anyway) are all screwed (unified special thread too) and cannot push out under freezing conditions.

These core plugs are only there due to the casting process and not designed as a pressure release device in the case of a block freezing, this is why a block will crack before a plug comes out.

Richard

Originally posted by Richard Farrant
These core plugs are only there due to the casting process and not designed as a pressure release device in the case of a block freezing, this is why a block will crack before a plug comes out.

Richard

I believe the casting process is the reason for all core plugs of whatever ilk surely? My point being that "commercial" drive-in and expand types et al do not "freeze-out", invariably the block goes first.

Along the same lines see also those devices known as Eze-outs, or easy-outs to us; they are never easy or out, and I am convinced they are designed by the Snap-off Tool Co. in conjunction with the World Federation of Spark Eroders.

In another case of brain going faster than fingers and short term memory of a goldfish, I did mean the B61 was never in production for British MVs, although was used in several civilian applications.

There are certainly a number of ways to get those eclipsed head nuts torqued down, starting from a feel-calibrated right arm with a shortish ring spanner to special tools, whatever.

R.